Antibumping device



Filed'oct. 27, 1941 2 Sheets-Sheet 1 Se t. 10, 1946. c. 1.. POELLI.NG 7,ANTIBUMPING DEVICE Filed Oct. 27, 1941 Patented Sept. 10, 1946 UNITEDSTATES PATENT OFFICE 2,407,226 ANTI BUMPING DEVICE George L. Doelling,St. Louis, Mo.

Application October 27, 1941, Serial No. 416,666

3 Claims.

This invention relates to improvements in anti-bumping devices used invaporization processes. More particularly, the invention relates toimprovements in anti-bumping devices that are designed to maintain aquantity of air or vapor in contact with the liquid contents of a still,evaporator, boiler, or distilling flask during the vaporization process.

It is one object of the present invention to provide an anti-bumpingdevice of simple construction that is effective in preventing bumping inthe distillation, vaporization, or boiling of liquids.

This invention relates to improvements in anti-bumping devices similarto the antibumping devices disclosed in my co-pending applications,Serial No. 334,949, entitled Antibumping devices, filed May 13, 1940,and issued November 4, 1941, as Patent No. 2,261,235, and Serial No.401,737, entitled Anti-bumping devices, filed July 10, 1941. Thisinvention is a continuation in part of the invention disclosed inapplications Serial No. 334,949, issued November 4, 1941, as Patent No.2,261,235, and Serial No. 401,737.

When bumping occurs, there is some superheating of portions of theliquid to be vaporized. The superheating of portions of the liquidreduces efficiency. Bumping also causes the entrainment of droplets ofliquid by the vapor, that foul the distillate. Preventing entrainmentnecessitates the provision of additional volume in the vaporizationapparatus that ordinarily is not needed. It can be seen, therefore, thatbumping reduces the efiiciency oi vaporization apparatus. By obviatingbumping with the devices and methods described herein, it is possible topromote smooth, even vaporization of liquid and thereby increase theefficiency of the vaporization process.

The phenomenon of bumping in vaporization processes, is particularlynoticeable upon restarting, after the distillation has been interruptedfor some reason. During the vaporization process, most of the air thatis trapped in an "antibumping device will gradually be displaced byvapor of the liquid to be vaporized. As long as the heating continues,the vapor in the device will contact the liquid and foster the smooth,even vaporization of the liquid. When, however, the vaporization processis temporarily suspended to make a cut, or for the addition of liquid tobe vaporized, or for any other reason, th contents cool somewhat. Thiscooling causes most or all of the vapor'in the "anti-bumping device tocondense into liquid. On re-heatin there may be insufiicient air oruncondensed vapor in the device to foster quiet vaporization of theliquid, and bumping may ensue. Especially is this true where thevaporization is done under reduced pressure. Where the vaporization isdone under reduced pressure, a good portion of the air initially held bythe. anti-bumping device is drawn out by the vacuum. The air thatremains in the device is, gradually replaced by vapor, until very littleair remains in the antibumping device. If the still is opened to permitinsertion of additional liquid to be vaporized, the pressure willincrease and the contents will cool. In such a case, practically all ofthe vapor in the anti-bumping device will condense. On

, re-heating, the liquid will quite probably bump.

v improved anti-bumping devices contemplated by the present inventionhave a new and diiferent means to foster smooth vaporization after aheating and cooling cycle. This means consists of a reservoir for air.This reservoir holds a supply of gas, air, or vapor that is normallyisolated from the main portion of the anti-bumping device. This supplyof gas, air, or vapor in the reservoir may contract during. the coolingcycle, but it will expand during the re-heating cycle and will combinewith the evolution of vapor from the liquid in the reservoir to chargethe anti-bumping device. This is quite useful because it automaticallyavoids all bumping after a heating and cooling cycle. It is, therefore,an

Y object of the present invention to provide an chambers.

anti-bumping device having a reservoir for air.

Anti-bumping devices can be used to advan-- tage in large vaporizationapparatus. Where this is the case, it is desirable to provide aplurality of chambers to foster smooth vaporization. Some of theanti-bumping devices disclosed in my'co-pending applications had aplurality of quite useful, but their utility can be increased even moreby the provision of a reservoir for air- It is, therefore, an object ofthe present invenv These anti-bumping devices are tion to provide ananti-bumping device having a plurality of interconnected chambers and areservoir for air.

Other objects and advantages of the invention will appear from thedrawings and accompanying description.

In the drawings and accompanying description, several preferredembodiments of the invention have been shown and described, but it isto. be understood that the drawings and accompanying description do notlimit the invention, and the invention will be defined by the appendedclaims.

In the drawings,

Fig. 1 is a partial cross-sectional view of a flask that shows a sideelevational view of an antibumping device positioned therein.

Fig. 2 is a partial cross-sectional view of aflask that shows a sideelevational view of another form of anti-bumping device positionedthere- Fig. 3 is a front elevational view of an antibumping device.

Fig. 4 is a partial cross-sectional view of a flask that shows a sideelevational view of another form of anti-bumping device therein.

Fig. 5 is a perspective view of an anti-bumping device.

Fig. 6 is a perspective view of another antibumping" device, and

Fig. 7' is a front elevational View of the antibumping device, shown inFig. 6.

Referring to the drawings in detail, in Fig- 1, a distilling flask isdenoted by the numeral I0. Positioned inside of the flask I0 andsecurely attached thereto is an anti-bumping device l2. The anti-bumpingdevice f2 consists of a hollow tube that is bent to form a chamber l4and a reservoir IS. The chamber M has a closed upper portion, an openingl8, and an opening 20. The opening I8 is positioned a distance below theclosed upper portion of the chamber l4, and the opening 20 is positionedbelow opening l8, but in the chamber portion of the tube. When liquid ispoured into the flask IE, it will enter the chamber I4 and the reservoirit through.

openings [8 and 20. The reservoir is open only at the bottom, so thelevel of the liquid in the reservoir will not rise much above the bendin the tube. The level of the liquid in the chamber It will rise to thelevel of opening I8. The liqu-id will, therefore, trap air in thereservoir l6 and the chamber I4, and will normally isolate the two fromeach other. Where desired, the anti-bumping device may be charged with agas instead of air. number of gases that are in the gaseous statethroughout the temperature range of the vapor ization process andpreferably are not freely soluble in the liquid to be vaporized. For thesake of convenience, the word air will be intended to comprehend such agas as well as air wherever the word air appears'in the specificationand claims. The reservoir will normally be isolated from the chamber bythe liquid to be vaporized, and will function to maintain the air in thereservoir separate from the vaporization occurring in the chamber.heated, the chamber [4 will operate to promotev even vaporization in themanner of the antibumping devicesv disclosedinmy co-pending applicationsSerial No. 334,949, issued November- 4, 1941, as Patent No. 2,261,235,and Serial No. 401,737. The liquid in the chamber l4 will contact theair in the upper portion of the chamber and will vaporize quite readily.The vapor that This gas maybe one of a When the flask is openings 28 and30.

is evolved from the liquid will issue from the chamber through openingI8. The ever-diminishing supply of liquid in the chamber will becontinually replenished by liquid entering through the lower opening 20.This liquid will be vaporized without any bumping. If the heatingoperation is temporarily suspended, a cooling of the contents of theflask will ensue. This cooling will result in a condensation of thevapor in the chamber l4. Where the heating cycle has been prolonged forsome time, the air initially entrapped in the chamber M will have beendisplaced practically completely by vapor of the. liquid. to bevaporized. In such a case, the. chamber will be practically completelyfilled with liquid during the cooling cycle. In a subsequent re-heatingcycle, the chamber I4 must be charged with air or vapor, or the liquidin the flask It] will bump. I'he device in Fig. 1 is charged by air orvapor from the reservoir l6. On re-heating, the air or vapor held in thereservoir will expand and will also foster the vaporization of theliquid in the reservoir. The combined action of vaporization andexpansion will quickly fill the reservoir with air and vapor, and willsoon cause vapor to move around bend [9 into chamber It. This willrecharge the device. The device is thus recharged after a heating andcooling cycle without any bumping whatever.

An anti-bumping device of slightly different design is shown in Fig. 2.This device consists of two hollow chambers 22 and 24, and a reservoir26. Each of the chambers 22 and 24 has an opening 28 in the side thereofand an opening 30 in the bottom thereof. The opening 28 in the side ofthe chamber is an outlet for vapor and the opening 30 in the bottom ofthe chamber is an inlet for liquid. The reservoir 26 is connected to thechamber 24 by a bend 32 and it has a closed upper end. This bendpreferably should not be above the level of the outlets 28 for vapor. Ifit were above the level of the outlets 28, the reservoir and .1 thechamber would not normally be isolated from each other by the liquid inthe chamber. The device is positioned in and securely attached to theflask l l When liquid is poured into the flask II, it enters thechambers 22 and 24 through The liquid will also enter the bend 32 andwill normally isolate the reservoir 26 from the chamber 24. Air will beentrapped in the upper portions of chambers 22 and 24, and will fosterthe smooth vaporization of the liquid. During distillation, the air inthe chambers will gradually be displaced by vapor until the chambershave practically no air in them. If the contents of the vaporizationapparatus are then cooled, the vapor in the chambers will condense intoliquid. On re-heating, the chambers must be recharged, or bumping willensue. The chambers are recharged automatically by the air or vapor fromthe reservoir 26. As the liquid gets warm, the air in the reservoir willexpand and will also foster vaporization of the liquid in the reservoir.The combined action of expansion and vaporization will fill thereservoir to overflowing and vapor will pass around the bend 32 into thechamber 24 and charge it. The evolution of vapor in chamber 24 will thencause bubbles of vapor to pass into chamber 22 through connecting member23. This member is preferably not above the level of the vapor outlets2B. The reservoir 26, therefore,

' automatically recharges. the anti-bumping dehas a closed upperportion. It also operates as a reservoir for air or vapor. Theanti-bumping device itself consists of two interconnected chambers 36and 38. The chamber 36 is located above chamber 38, but is connected toit. The chamber 36 has at least one opening 40 in addition to theopening 42 where it is connected to chamber 38. Chamber 38 has at leasttwo openings 44 and 46. When this device is placed in a vaporizationapparatus and liquid is poured into the apparatus, liquid will fill theportions of chamber 36 below the opening 40, will fill the portion ofthe chamber 38 below the opening 44, and will fill the bend 48. The restof the device will be filled with air that will-foster even vaporizationof the liquid. The utility of this particular device is thatvaporization can take place simultaneously at diiferent levels in theliquid. As the liquid vaporizes and its level in the still falls,evolution of vapor will continue from openings 40 and 44 until theliquid level is below opening 40. Vapor will continue to issue fromopening 44 until the liquid level is below the opening 44. After this,vaporization will occur from the opening 46 until the liquid level fallsto this point. Atthis time, the ratio of the surface of the liquid tothe volume of the liquid is so large that, the problem of the bumping"is no longer of any concern. If the vaporization process is suspendedwhile there is still a sizeable quantity of liquid in the vaporizationapparatus,

the contents will cool down and the vapor in chambers 36 and 38 willcondense into liquid. On re-heating, the device will be rechargedautomatically by air and vapor issuing from the reservoir 34. Air orvapor from the reservoir will be caught in chamber 38. This air or vaporwill foster vaporization in chamber 38 until the upper portion of thechamber is filled with vapor. Vapor will then bubble out of holes 42 and44. The vapor passing through-the opening 42 will be caught in chamber36 and will charge the chamber. In this way. the device will berecharged without any bumping of the liquid.

Fig. 4 shows an anti-bumping device similar to the device shown inFig, 1. This device has a chamber 49 similar to chamber l4 and areservoir 50 similar to reservoir 1 6. The device is different from thedevice shown in Fig. 1, in that this device is not permanently attachedto the vaporization apparatus and may be removed. The operation of thisdevice is substantially identical With the operation of the device shownin Fig. 1.

Fig. 5 shows another form of anti-bumping device. This form of deviceconsists of a reservoir 52 and a chamber -54. The reservoir is formedfrom a hollow tube with a closed upper end and extends into the chamber54. The chamber 54 has an open bottom and has notches 56 in its loweredges that function as outlets for vapor. The bottom of reservoir 52 hasa notch 58 that is preferably not above the level of the notches 56. Thedevice may be made so that it can stand by itself or it may be made tolean against an upper portion of the vaporization apparatus. When thedevice is placed in vaporization apparatus containing liquid, the liquidWill enter the bottom of the chamber and the bottom of the reservoir.Air will be entrapped in the upper portions of the reservoir and thechamber. Th chamber and the reservoir will normally be isolated fromeach other by the liquid in the chamber. After a heating and coolingcycle, the vapor in the chamber will practically all have condensed intoliquid. The device is automatically recharged by re-heating the liquid,since the air and vapor in the reservoir will completely fill thereservoir and will cause bubbling at the bottom of the reservoir. Thisbubbling will charge the chamber. This device is particularl usefulbecause it maintains vapor in contact with the liquid near the source ofheat.

Figs. 6 and 7 shows another form of antibumping device. This devicecomprises two in terconnected chambers 60 and 62 and a reservoir 64connected to chamber 62. The chamber 62 has an open bottom and notches66 in the edges near the bottom of the chamber for outlet of vapor.Chamber 6D has an opening 68 and an opening 10 where it communicateswith chamber 62. The opening 10 is preferably not above notches 66.Reservoir 64 hasa closed upper portion and is connected to chamber 62 byan opening 12 that is preferably not above notches 66. The reservoir 64is ordinarily isolated from chamber 62 by the liquid in the bottom ofthe chamber 62. The recharging of the device is substantially the sameas the recharging of the device in Fig. 3. The devices provided by theinvention effectively and automatically prevent "bumping during heating,cooling, and re-heating cycles.

The drawing has shown the devices mounted in distilling flasks, but thisWas done only for the sake of clarity and convenience. These devices canbe used in any kind of vaporization apparatus. The devices may be madeso they are selfsupporting or they may be used in vaporizationapparatus, provided with means to hold the devices in the operatingposition.

The anti-bumping devices of this invention comprise a chamber and areservoir for air. chamber may be made in any suitable shape but it musthave a closed upper portion, an inletfor liquid, and an outlet forvapor. In some cases,,a single opening can serve the dual purpose ofinlet for liquid and outlet for vapor, and the chamber will then haveonly one opening. The reservoir is preferably connected to the chamberat a point not higher than the outlet for vapor. Furthermore, at least apart of the reservoir is preferably positioned higher than the bottom ofthe chamber so the reservoir will trap air therein.

Bumping is objectionable for many reasons. Many of these are detailed inmy co-pending applications, Serial Numbers 334,949, issued November 4,1941, as Patent No. 2,261.235 and 401,737. Not the least objection tobumping is the loss of efficiency it causes. I have made tests with theanti-bumping devices I have invented, and find that the use of thesedevices increases the rate of vaporization. This is the case where thedevice is used in glass, metal lined with glass, metal, or othervaporization apparatus. In making the tests, every precaution was takento avoid errors. Two stills were placed in the same hot-water bath andtheir receivers were both connected to the same vacuum line. A stirrerwas used to secure The,

anteven temperature throughoutthe water in the bath. Qne .of the stillswas equipped with the anti-bumping'device shown. inFig. 3, while theother. had no"anti-bumping device. To obviate errors,:the anti-bumpingdevice was taken from theonesstill and placed in the other and the testrepeated.

In .one such series of tests, two 500 cc. copper flasks were eachcharged with 300 cc. of distilled water. "A constant bath temperaturewas maintained and'a constant vacuum-was maintained. Atotal of eightdistillations (four'pairs) were run forforty mintues each. The combinedresults of the "runs 'show that four runs with the antibumping devicevaporized 761.1 grams .of water, while four parallel .runs without ananti-bumpingrdevice vaporized-only 465.0 grams of water. By:use or theanti-bumping device, 63.7% more waterwas vaporized in the .same lengthof time.

Similar tests were also run with glass-distilling flasks. These testsshowed that the use of an anti-bumping device can increase the amount ofvaporization by 100 per cent or more. These tests clearly. show that itis possible to increase theefiiciency of vaporization processestremendously by theuse of anti-bumping devices.

Whereas the drawings and accompanying description have shown anddescribed preferred embodiments'of the invention, it isobvious to thoseskilled in the-art that various changes in form can be made withoutafie'cting the scope of the invention.

What I claim is:

.1. In combination, a vaporizer and an antibumping device'comprising anintegral structure containing more thantwo chambers, within thevaporizer and in close proximity to the heating surface thereof, onechamber being sealed and extending above the others and connectingtherewithby a discharge passage, said first chamber being withoutopening :above the point of discharge, :said other chambers being openat the bottoms thereof 'and each having adischarge opening thereabovebut at suflicient distance below the top of the chambers-toigivea'closed space above'said discharge openings.

2. In combination, 'a vaporization apparatus and an anti-bumping device,said anti-bumping device comprising aniintegral structure containingmore than two chambers, one chamber being sealed and extending above theothers and connecting therewith by a discharge passage, 'said firstchamber being without opening :except through the :dischargepassage,said other chambers each having an openingin proximity .to the bottomthereof and a discharge opening thereabove but at a sufiicient distancebelow the top of such :chamber to give a closed space above saiddischarge opening, saidanti-bumping device being positionedincloseproximity-to the bottom of said vaporization apparatus so that it willbe normally surrounded by and substantially immersed in the liquid beingvaporized and'willbe near the heating surface of said vaporizationapparatus.

3. In. combination, a vaporization apparatus and a.removable'anti-bumping device positioned within and resting on thebottom of the said vaporization apparatus so that it will be normallysurrounded by and'substantially immersed in the liquid being vaporizedand will be near the heating surface of the said vaporization apparatus,said anti-bumping device comprisingan integral structure containing morethan two chambers, one chamber being integrally sealed'and extendingabove the others andconnecting therewith by a discharge passage, saidfirst chamber being without opening except through the dischargepassage, said other chambers, each having an opening in proximity to thebottom thereof and a discharge opening'thereabove but at a sufficientdistance below the top of such chamber to give a closed. space abovesaid discharge opening, the upper part of said anti-bumping device beingadaptedto engage a portion of the vaporization apparatus and'therebymaintain the said device in the operating position.

GEORGE L. DOELLING.

